AAD Integration

CAPZ can be configured to use Azure Active Directory (AD) for user authentication. In this configuration, you can log into a CAPZ cluster using an Azure AD token. Cluster operators can also configure Kubernetes role-based access control (Kubernetes RBAC) based on a user’s identity or directory group membership.

Create Azure AD server component

Create the Azure AD application

export CLUSTER_NAME=my-aad-cluster
export AZURE_SERVER_APP_ID=$(az ad app create \
    --display-name "${CLUSTER_NAME}Server" \
    --identifier-uris "https://${CLUSTER_NAME}Server" \
    --query appId -o tsv)

Update the application group membership claims

az ad app update --id ${AZURE_SERVER_APP_ID} --set groupMembershipClaims=All

Create a service principal

az ad sp create --id ${AZURE_SERVER_APP_ID}

Create Azure AD client component

AZURE_CLIENT_APP_ID=$(az ad app create \
    --display-name "${CLUSTER_NAME}Client" \
    --native-app \
    --reply-urls "https://${CLUSTER_NAME}Client" \
    --query appId -o tsv)

Create a service principal

az ad sp create --id ${AZURE_CLIENT_APP_ID}

Grant the application API permissions

oAuthPermissionId=$(az ad app show --id ${AZURE_SERVER_APP_ID} --query "oauth2Permissions[0].id" -o tsv)
az ad app permission add --id ${AZURE_CLIENT_APP_ID} --api ${AZURE_SERVER_APP_ID} --api-permissions ${oAuthPermissionId}=Scope
az ad app permission grant --id ${AZURE_CLIENT_APP_ID} --api ${AZURE_SERVER_APP_ID}

Create the cluster

To deploy a cluster with support for AAD, use the aad flavor.

Make sure that AZURE_SERVER_APP_ID is set to the ID of the server AD application created above.

Get the admin kubeconfig

clusterctl get kubeconfig ${CLUSTER_NAME} > ./kubeconfig
export KUBECONFIG=./kubeconfig

Create Kubernetes RBAC binding

Get the user principal name (UPN) for the user currently logged in using the az ad signed-in-user show command. This user account is enabled for Azure AD integration in the next step:

az ad signed-in-user show --query objectId -o tsv

Create a YAML manifest my-azure-ad-binding.yaml:

apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: my-cluster-admin
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: cluster-admin
subjects:
- apiGroup: rbac.authorization.k8s.io
  kind: User
  name: your_objectId

Create the ClusterRoleBinding using the kubectl apply command and specify the filename of your YAML manifest:

kubectl apply -f my-azure-ad-binding.yaml

Accessing the cluster

Install kubelogin

kubelogin is a client-go credential (exec) plugin implementing Azure authentication. Follow the setup instructions here.

Set the config user context

AZURE_ENVIRONMENT=AzurePublicCloud
kubectl config set-credentials ad-user --exec-command kubelogin --exec-api-version=client.authentication.k8s.io/v1beta1 --exec-arg=get-token --exec-arg=--environment --exec-arg=$AZURE_ENVIRONMENT --exec-arg=--server-id --exec-arg=$AZURE_SERVER_APP_ID --exec-arg=--client-id --exec-arg=$AZURE_CLIENT_APP_ID --exec-arg=--tenant-id --exec-arg=$AZURE_TENANT_ID
kubectl config set-context ${CLUSTER_NAME}-ad-user@${CLUSTER_NAME} --user ad-user --cluster ${CLUSTER_NAME}

To verify it works, run:

kubectl config use-context ${CLUSTER_NAME}-ad-user@${CLUSTER_NAME}
kubectl get pods -A

You will receive a sign in prompt to authenticate using Azure AD credentials using a web browser. After you’ve successfully authenticated, the kubectl command should display the pods in the CAPZ cluster.

Adding AAD Groups

To add a group to the admin role run:

AZURE_GROUP_OID=<Your Group ObjectID>
kubectl create clusterrolebinding aad-group-cluster-admin-binding --clusterrole=cluster-admin --group=${AZURE_GROUP_OID}

Adding users

To add another user, create a additional role binding for that user:

USER_OID=<Your User ObjectID or UserPrincipalName>
kubectl create clusterrolebinding aad-user-binding --clusterrole=cluster-admin --user ${USER_OID}

You can update the cluster role bindings to suit your needs for that user or group. See the default role bindings for more details, and the general guide to Kubernetes RBAC.

Known Limitations

  • The user must not be a member of more than 200 groups.